Disk drive heads are sensitive devices that can be damaged through excessive use and/or excessive electrical stress (e.g., electrostatic discharge, or “ESD”). Head damage may include a misalignment of the magnetic orientation of one the head's components, or layers. For example, a pinned layer of the head is intended to maintain a particular magnetic orientation. A free layer of the head, on the other hand, has a magnetic orientation that moves about freely as the name suggests. The pinned layer and the free layer of a given head operate in tandem to detect electromagnetic impressions on a magnetic disk of the disk drive. Detection of the electromagnetic impressions occurs by means of changing disk drive head resistance due to the changing magnetic orientation of its free layer with respect to its pinned layer. Excessive use and/or excessive electrical stress have a tendency to misalign the magnetic orientation of the pinned layer of the head. When the magnetic orientation of the pinned layer of the head becomes misaligned with respect to an optimal magnetic orientation, detection of magnetic impressions on the disk may be impaired and data quality may degrade.
Certain methods exist which attempt to realign the magnetic orientation of the pinned layer of a head by transferring a pulse of electric current directly to the disk drive head. For example, as electric current is transferred to the pinned layer of the head, the current tends to realign the magnetic orientation of its pinned layer. However, as disk drive head sizes have decreased in an effort to enhance/accommodate increased data storage capacity of the disk drive, the disk drive heads have become increasingly sensitive to certain electrical effects. Because smaller disk drive heads are more electrically sensitive than larger disk drive heads, pulsed electric current methods often exacerbate the problem of magnetic alignment by causing physical damage to the disk drive head, which may not be repairable.